Upgraded better_errors gem

Author: jasnow

Gemfile.lock

@@ -51,7 +51,7 @@ GEM
     ast (2.4.0)
     backports (3.11.4)
     bcrypt (3.1.12)
-    better_errors (2.5.0)
+    better_errors (2.5.1)
       coderay (>= 1.0.0)
       erubi (>= 1.0.0)
       rack (>= 0.9.0)